A variety of different reel lowering devices for transferring a reel from a supporting rack for storing empty reel bars into a transfer means to move the reel bars into a winding position have been proposed and many such devices are currently in use. For example U.S. Pat. No. 1,949,997 issued Mar. 6, 1934 to Fourness describes a paper winder wherein empty cores are carried from a lower rack via a pair of arms and moved into winding position against a winding drum to form a roll of paper. The shaft of the paper core is transferred from grooves or slots in the arms transferring the core to the winding position into co-operating slots formed in a second pair of transfer arms that carry a finished or wound roll of paper into a second storage rack located above the storage rack for empty reels. This device provides for the loading and unloading of reels and wound paper rolls respectively from a winding position but is a relatively expensive and cumbersome piece of equipment.
U.S. Pat. No. 2,508,566 issued May 23, 1950 to Dunton describes a web roll backstand and provides for a transfer of a wound roll to an unwind station and removal of the cores. A pair of arms are used to make the transfer into the unreeling position and a second pair of arms are used to transfer the empty reel or core to a second storage position. Although this device is not a device for transferring empty reels into a transfer arm it does show the use of spaced arms to make the transfer of the roll into an operating position.
U.S. Pat. No. 2,989,262 issued June 20, 1961 to Hornbostel teaches the use of gravity to roll a plurality of empty cores and apply the cores one at a time from an inclined storage device into a loading position where they are picked up by a transfer arm and moved into winding position between a pair of winding drums. The mechanism for controlling the flow of empty cores down the relatively steep incline of the storage device leads to significant complications in this structure of the winder.
Yet another example of a reel loader is shown in U.S. Pat. No. 3,586,253 issued June 22, 1971 to Gilbank et al. In this device empty reels are loaded onto an upper rack formed by a pair of rails having an abutment stop at their lower ends so the empty reels move down the rails to the abutment stop. A pair of lifting and lowering arms are provided which lifts each empty reel over the abutment and permits it to roll to the opposite side thereof and then lowers the reel into the reel transfer device. The operations of the reel lowering arms in the arrangement require both the lifting over the abutment, transverse movement to direct the reel to the opposite side of the abutment and then lowering of the reel into the transfer device. The opposite side of the abutment in this case operates as a cam to hold the reel in position during the initial phases of lowering of the lowering arms so that there is a controlled movement of the reel along the lowering arms. Obviously the reciprocal motion of the arm during loading complicates the operation of the lowering arms in that they first must move upward to lift the reel bars above the abutment and then downward after the reel bars have moved along the arm to the opposite side of the abutment into a transfer position.
U.S. Pat. No. 3,877,654 issued Apr. 15, 1975 to Randpalu et al. utilizes transfer arms as a transfer device in the normal manner to move a reel bar into winding position and also as a lowering mechanism. The transfer arms are extended so that the clamp may move along the arms to an upper position to receive reels located on the storage rack thereabove. Clearly, such extension of the transfer arms requires a controlled movement of the reels along the storage rack to permit the transfer arms to rotate and requires a more elaborate clamping mechanism which is transported along the transfer arms.
In my copending U.S. patent application Ser. No. 874,160 filed June 13, 1986 there is disclosed a reel bar loader device having a pair of lowering arms onto which the reel bars are loaded one at a time. The lowering arms pivot from an upper position adapted to receive a reel bar on a supporting surface thereof to a lower transfer position while the reel bar rolls along the length of the surface into contact with an abutment on the arms. The reel lowering arms provide a cam stop that moves into stopping position to stop movement of reel bars into a loading position when the lowering arms are not in their upper position.
None of the above reel lowering devices provide for constant nip pressure or tension to be applied to the reel bar as it is lowered into a winding position remote from its initial empty position.